Apparatus for producing foam for extinguishing fires



March 11, 1941. E GQHRE 2,234,631

APPARATUS FOR PRODUCING POM! FOR EXTINGUISHIfiG FIRES Fil 1.ed Jan. [50, 1959 2 Sheets-Sheet 1 [/7 wen/or I 4y I 77 I E. GGHRE 2,234,631 APPARATUS FOR PRODUCING FOAM FOR EXTINGUISHING FIRES Manila 11,1941.

Filed Jan. '50, 1959 2 Sheets-She et 2 UNITED STATES 2,234,631 APPARATUS non raonucmc FOAMFOR nx'rmemsnmd FIRES Ernst Giihre,

' Concordia Dortmund, Germany, Germany Dortmund, German assignor to Elektrizitats Aktiengesellschaft,

a joint stock company or Application. January so. 1939, Serial No. 253.497

- y In Germany November 9, 1938 .6 Claims. (01. 261-46) My invention relates to improvements in apparatu for producing 10am for extinguishing flre, and more particularly in apparatus in which a suitable liquid is intimately mixed with air or 5 another gaseous fluid for producing foam ,by electing the said components under pressure or by vacuum from nozzles. The object of the improvements is to provide an apparatus by means of which the jet of liquid is readily broken up and id intimately mixed with the air or gas in the form of team. With this object in view my invention consists in forming the liquid and the gaseous fluid in films and causing the said films to act on each other so as to be intimately mixed. In

" the practice of the invention I prefer to cause the liquid and the gaseous fluid to impinge upon a surface which preferably is shaped along stream lines so as to avoid loss of pressure which is not directly used for mixing the components.

WI For the p se. of explaining the invention several examples embodying the same havebeen illustrated in the accompanying drawings, in which v Fig. l is a somewhat diagrammatical elevation at partly in section showing the apparatus.

Fig. 2 is a similar elevation partly in section showing a modification in which the components irom which the foam is' produced meet one another in the form of three films, and

Fig. 3 is a similar sectional elevation showing another modification in which the gaseous fluid, the liquid and the liquid to be added thereto for enabling the same to be transformed into foam are separately formed into films.

In the example shown in Fig. l the foam pro ducing apparatus comprises a tubular member consisting of a cylindrical section a. and a tapering section b, a cup-shaped member 0 which is closed at its bottom and open at its top and 40 which has its wall shaped along streamlines, the' said member c, being located concentrically within the top part of the cylinder a, and an oval hollow body 0 located concentrically within the open upper part of the member c and likewise i5 shaped along stream lines. Between the top part ot the member 0 and. the cylindrical wall a an annular passage d, and between the top part of the member 0 and the body e a chamber vand an annular passage 1 are formed. The member to c is flxed to the cylinder a by narrow tubular studs h the cross-section of which is narrow so that the resistance opposed to the flow of the fluid through the passage dis as small as possible. The body e is flxed to the conical part!) by thin 5 ribs m which preferably are edge shaped at their ends in order to'reduce the resistance opposed to the flow or the fluids. At its bottom the cylinder :1 is provided with a flange n and hooks o by means of which it may be attached to a supply of fluid. The tubular studs h are likewise adapted to be connected to a supply of fluid, or they are open to the outer air.

In the example shown in which the foam is to be produced is supplied through the tubular member a from the bottom thereof, and it impinges upon the member c and is, formed thereby into an annular film flowing through the annular passage d and delivered therefrom into the tapering section b. The gaseous fluid is supplied through the tubular studs h v into a chamber a and it impinge upon the bottom part of the body e and i transformed thereby into an annular fllm delivered from the annular passage 1. Thus the films of liquid and gaseous fluid are delivered one beside the other and concentrically of each other from the passages d and f, .and the said films are in frictional engagement with each other. Thereby the film of liquid is readily broken up and mixedwith the gaseous fluid so that a foam is produced, :the formation of a foam being assisted by the conical shape of the section b of the tubular member.

The modification shown in Fig. 2 is similar to the one illustrated in Fig. 1, and the same letters of reference have been used to indicate corresponding parts. However, the construction is .modifled in so far as the tubular member for the supply of the liquid'and the delivery oi! the foam is made in two separate sections, viz. the cylindrical member a and the conical member in, the bottom part of the member In being placed around the top part of the member a and forming an annular passage is therewith. Thus, the liquid delivered from the annular passage'd acts by suction on the air within the annular passage -k and it draws the same in the form or an annular film upwardly and into the conical membeer in. Thus, thefllm otliquid delivered from the passage d is enveloped internally and exter nally by a fllm 01a gaseous fluid, the said internaland external fluid being either air or anpther gas. Y f

It will be understood that means may be provided ror supplying the gaseous fluid through the annular passage is under pressure.

The constructior shown in Fig. 3 is similar to .theone distinguished from the said figure, the member c shown in Fig. ,3 is provided with a single inlet pipe to to which a p pe or hose 2 is attached.

Fig. 1 the liquid from described with reference to Fig. 2. As

In the apparatus shown in Fig. 3 water is supplied through the pipe a, and a foam producing medium such as a solution of soap is supplied to the member c through the inlet pipe 10. Air or gas is supplied through the passage k by the sucking action of the water delivered from the passage d. The soap solution delivered from the passage f is mixed with the water and the said mixture is transformed into foam by the air or gas drawn in through the passage is.

I have found that in the foam producer the liquid and gaseous fluids find a small resistance,

and that the output of foam is exceedingly high.

- This result is attained by bringing the foam producing components into contact with each other with large surfaces, so that the fluids are able to permeate each other with a minimum of resistance. v

I claim:

1. An apparatus for producing foam from a liquid and a gaseous fluid, comprising a substantially rectilinear tubular body having an-intake end constructed for connection with a supply of liquid under pressure and a delivery end, a cup shaped member disposed concentrically within said tubular body and forming an annular passage therewith which is open at the side of said delivery end, a member disposed concentrically within said cup shaped member to form an annular passage therewith, which passage is open near the open end of said passage provided by said tubular body and said cup shaped member, said cup shaped member and said member disposed concentrically within the same having their walls gradually reduced in cross-section from the said delivery end towards the intake and of said tubular body and to points near the axis of said tubular body, and a tubular member for connecting said annular passage provided by said cup shaped member and said member disposed concentrically within the same with a supply oi a gaseous fluid.

2. An apparatus for producing foam from a. liquid and a gaseous fluid as claimed in claim 1, in which the said cup shaped member and said member disposed concentrically within the same are rounded at their gradually reduced portions.

3. An apparatus for producing foam from a liquid and a gaseous fluid as claimed in claim 1, in which the said cup shaped member and said inember disposed concentrically within the same are rounded at their gradually reduced portions and in which the said member disposed concentrically within said cup shaped member is formed along stream lines and has a portion of its wall extendin from said annular passages into said tubular ody, said portion being gradually reduced in cross-sectional area from said annular passages towards the delivery and of said tubular body so as to produce an annular passage between the same and said first named tubular body which is gradually increased in crosssection.

4. An apparatus as claimed in claim 1, in which the said tubular member is continued beyond the said passages into an inwardly tapering portion.

5. An apparatus as claimed in claim 1, in which the said tubular member is continued from the said passages into a tapering pipe forming a concentric passage around the delivery ends oi said passages.

6. An apparatus for producing foam from liquid and gaseous fluids comprising a body formed with more than two concentric passages having their delivery ends adjacent .to one another, and means to force liquid and gaseous fluids alternately through said passages. the innor passages being provided with rounded sur-,

faces disposed transversely of the flow of the fluids therethrough and forming annular passages therein. 1

ERNST GOHRE. 

